Thousands of workers at Foxconn went on strike Friday following demands from their bosses that they improve the quality of their work without the proper training, according to China Labor Watch (CLW). Workers also complained that they were required to work during holidays.

CLW says three to four thousand workers went on strike and many are responsible for producing Apple's new iPhone 5. iPhone 5 production was said to be in "a state of paralysis for the entire day." We've reached out to Apple for comment and will update if a representative responds.

Here's the meat of CLW's report:

The majority of workers who participated in this strike were workers from the OQC (onsite quality control) line. According to workers, multiple iPhone 5 production lines from various factory buildings were in a state of paralysis for the entire day. It was reported that factory management and Apple, despite design defects, raised strict quality demands on workers, including indentations standards of 0.02mm and demands related to scratches on frames and back covers. With such demands, employees could not even turn out iPhones that met the standard. This led to a tremendous amount of pressure on workers. On top of this, they were not permitted to have a vacation during the holiday. This combination of factors led to the strike.

The report also says there was a fight between workers and their bosses that caused some people to be sent to the hospital.